Wingsuit research

Haha, reading the old threads is so much fun! Here's a fun one:

/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=3100837;page=1;mh=-1;;sb=post_latest_reply;so=ASC

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If you can train your 70 horny men of questionable orientation to hold their hands and form a superlong flying wing, the vortices rolling from the wingtips will cancel each other and you essentially get a giant aspect ratio with L/D = 70:1! You'll be able to circle Lake Elsinore from sunrise to sunset catching thermals and land the whole formation without those stupid chutes.

420 foot wide connected formation with amazing glide ratio... now THAT'S a REAL world record!

Those were interesting times, people were actually interested in wingsuit progress then! (Unfortunately, it was stopped right about that time by T-intersection, I mean, T-planform. Haven't moved from there in the past 10 years!)

aonsquared

His stuff has probably been rejected by Wikipedia (they have strict rules against self-promotion)

Never submitted anything to Wikipedia and never will.

Self-promotion is what 99% of the wingsuit article on Wiki is:

https://en.wikipedia.org/wiki/Wingsuit_flying

I don't give a fuck about self-promotion. Since I gave up on seeing any hope from existing WSMs, I post here for new wingsuiters, who are not familiar with old stuff they may find interesting, as well as relatively new stuff, and hopefully it won't take that long (another 12 years) for new WSM to be born and embrace the new technology and delight all of us with refreshing line of wingsuits, backed up by hard numbers, not marketing BS.

aonsquared

***WSE are classic and eternal

They'll last as long as the people who think they're correct, and the server hosting on his website.

It's on web.archive.org, as well as countless other servers, search engines, people's computers, my apps on app stores (which are also duplicated by various app discovery sites)... The information on the web these days is indistructible. (no wonder - it's evolution of military network design built to withstand nuclear war)

Whatever anyone posts on the web stays there forever, in one form or another. That's why it's fun to come back many years later and read silly posts by all the stooges, including many "airspice engineers" (yeah, many of those who trolled in my threads back 12 years ago, were/are airspices.)

yuri_base

***His stuff has probably been rejected by Wikipedia (they have strict rules against self-promotion)

Never submitted anything to Wikipedia and never will.

Self-promotion is what 99% of the wingsuit article on Wiki is:

https://en.wikipedia.org/wiki/Wingsuit_flying

I don't give a fuck about self-promotion. Since I gave up on seeing any hope from existing WSMs, I post here for new wingsuiters, who are not familiar with old stuff they may find interesting, as well as relatively new stuff, and hopefully it won't take that long (another 12 years) for new WSM to be born and embrace the new technology and delight all of us with refreshing line of wingsuits, backed up by hard numbers, not marketing BS.

aonsquared

***WSE are classic and eternal

They'll last as long as the people who think they're correct, and the server hosting on his website.

It's on web.archive.org, as well as countless other servers, search engines, people's computers, my apps on app stores (which are also duplicated by various app discovery sites)... The information on the web these days is indistructible. (no wonder - it's evolution of military network design built to withstand nuclear war)

Whatever anyone posts on the web stays there forever, in one form or another. That's why it's fun to come back many years later and read silly posts by all the stooges, including many "airspice engineers" (yeah, many of those who trolled in my threads back 12 years ago, were/are airspices.)

You sure promote yourself a lot for not caring about it.


Yuri, why don’t you post your equation derivations? Or provide them somehow. I may only be an engineer with a math minor but I know some people with masters/PhD that would love to look at them.

Wiki article is a disgusting pile of self-promotion.

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With training, wingsuit pilots can achieve sustained glide ratio of 2.5:1 or more.[6]

Link 6 leads to tonysuits.com, article on Dean Potter. Why? What it has to do with GR? (other that to point search bots to index the site) Self-promotion!

Quote

The main surface is typically made from ripstop nylon, with various materials used to reinforce the leading edge, and reduce drag.[8]

Link 8 leads to Aura3 on squirrel.ws. Why? Is it the only suit made of various materials? Self-promotion!

Quote

BASE jumping in its modern form has existed since at least 1978, but it was not until 1997 that Patrick de Gayardon made some of the first ever wingsuit BASE jumps combining the two disciplines.[9]

Link 9 leads to flylikebrick.com. Why? Is that some official historical record? Self-promotion!

Quote

Since 2003, many BASE jumpers have started using wingsuits, giving birth to wingsuit BASE.[10]

Link 10 leads to The Great Book of BASE ISBN. Self-promotion!

Quote

The longest verified wingsuit BASE jump is 7.5 kilometres (4.7 mi) by the American Dean Potter[30]

Link 30 leads to tonysuits.com again. If the record is "verified" by official entity, the link should go there. Self-promotion!

Quote

The current world record for greatest average horizontal speed within the performance competition rules, i.e. within 1,000 m (3,300 ft) of vertical distance, was set on 23 October 2016, U.S. wingsuit pilot Joe Ridler set the world record for the fastest speed reached in a wingsuit of 374.8 km/h (232.9 mph).[32]
The current world record for longest horizontal distance covered within the performance competition rules, i.e. within 1,000 m (3,300 ft) of vertical distance, was set on 23 October 2016 by U.S. wingsuit pilot Alexey Galda with a distance of 5.996 km (3.726 mi).[32]

This BS is exposed above, link 32 goes to Paralog. Self-promotion!

Quote

Wingsuits were showcased in the 1969 film, The Gypsy Moths, starring Burt Lancaster and Gene Hackman.[38]

Link 38 goes to WWL. WTF WWL has to do with Gypsy Moths?! Self-promotion!

External links go to "How to Start Wingsuit Flying & Prices, Where to Learn, Videos, Risks & News" wingsuitfly.com and flylikebrick.com (2nd time!).

This is the state of the union in wingsuiting today. BS, self-promotion, fake records, lies, hiding truth, stagnation, no scientific approach.

Very sad...

yuri_base

Wiki article is a disgusting pile of self-promotion.

Quote

With training, wingsuit pilots can achieve sustained glide ratio of 2.5:1 or more.[6]

Link 6 leads to tonysuits.com, article on Dean Potter. Why? What it has to do with GR? (other that to point search bots to index the site) Self-promotion!

***The main surface is typically made from ripstop nylon, with various materials used to reinforce the leading edge, and reduce drag.[8]

Link 8 leads to Aura3 on squirrel.ws. Why? Is it the only suit made of various materials? Self-promotion!

Quote

BASE jumping in its modern form has existed since at least 1978, but it was not until 1997 that Patrick de Gayardon made some of the first ever wingsuit BASE jumps combining the two disciplines.[9]

Link 9 leads to flylikebrick.com. Why? Is that some official historical record? Self-promotion!

Quote

Since 2003, many BASE jumpers have started using wingsuits, giving birth to wingsuit BASE.[10]

Link 10 leads to The Great Book of BASE ISBN. Self-promotion!

Quote

The longest verified wingsuit BASE jump is 7.5 kilometres (4.7 mi) by the American Dean Potter[30]

Link 30 leads to tonysuits.com again. If the record is "verified" by official entity, the link should go there. Self-promotion!

Quote

The current world record for greatest average horizontal speed within the performance competition rules, i.e. within 1,000 m (3,300 ft) of vertical distance, was set on 23 October 2016, U.S. wingsuit pilot Joe Ridler set the world record for the fastest speed reached in a wingsuit of 374.8 km/h (232.9 mph).[32]
The current world record for longest horizontal distance covered within the performance competition rules, i.e. within 1,000 m (3,300 ft) of vertical distance, was set on 23 October 2016 by U.S. wingsuit pilot Alexey Galda with a distance of 5.996 km (3.726 mi).[32]

This BS is exposed above, link 32 goes to Paralog. Self-promotion!

Quote

Wingsuits were showcased in the 1969 film, The Gypsy Moths, starring Burt Lancaster and Gene Hackman.[38]

Link 38 goes to WWL. WTF WWL has to do with Gypsy Moths?! Self-promotion!

External links go to "How to Start Wingsuit Flying & Prices, Where to Learn, Videos, Risks & News" wingsuitfly.com and flylikebrick.com (2nd time!).

This is the state of the union in wingsuiting today. BS, self-promotion, fake records, lies, hiding truth, stagnation, no scientific approach.

Very sad...

Lol, now that’s an impressive off topic word salad. What was your point in all of that? You’re still pushing your app, you’re still promoting your equations. Why do you think the world records are fake? Were those pilots not moving the fastest and furthest across the ground?

Back on topic yuri, where are those derivations I asked for? Why won’t you say what you believe the magic L/D number translates to for wingsuit flight?

yuri_base

On 2016-10-23, two guys went to Rochelle (only 2!) and set "world records" in distance and speed.

As a result, they essentially fucked up other capable guys who fly (relative to air) as good or almost as good as these guys, but are now far below in the table of records, for a long time (2 years already). Only because these 2 guys did "wind-shopping" and did a downwind jump in hurricane-strength uppers.

These "records" are as moronic as someone recording a GPS track of their run to bathroom on a jet liner, extracting a 100m length of it, and claiming on Wikipedia that they ran 100m in only 0.4s, much faster than Usain Bolt's 9.58s.

Here's my proposal to Paralog:

1. Stop this fucking nonsense, games with wind, fake "records", cheating.

2. Mandate the following rules, for any distance/speed track:

Rule A. The ground track must be a straight line with no more than 100m deviation from the line start-finish of 1000m altitude window.

Rule B. The ground track heading is established before each load as a line that is at an angle to cross-wind line (in downwind direction) equal to arctan of half wind speed divided by average horizontal speed of top 3 pilots in previous competition or maybe a test run before competing. This is to make the ground speed as close to air speed as possible, as the crosswind line will bisect the airspeed-groundspeed-windspeed triangle. Pilot's actual start-finish line should not deviate from this heading more than 5 degrees.

Rule C. No tracks are accepted if winds at 500m window level are more than 20kn. This is to minimize the difference between groundspeed and airspeed, since the bisecting cannot be done perfectly.

3. Standardize all speed results to sea level by dividing the speeds by a factor of [square root of (density at sea level) /divided by/ (density at middle level of 1000m window)]

4. Standardize all time results to sea level by multiplying the times by a factor of [square root of (density at sea level) /divided by/ (density at middle level of 1000m window)]

5. With wind-corrected ground tracks and standardized speeds and times, add calculated L/D to graphs according to the formula

L/D = (GR + z)/(1 - GR*z)

where z is dimensionless ratio z = ax/(g - ay), ax is horizontal acceleration, ay vertical, g acceleration due to gravity. (ax and ay are calculated from Vx, Vy data as derivatives.) GR here is glide ratio relative to air (which should be close to ground GR if the flights follow the above rules).

Then we can stop talking all this BS and cheating and not only give all pilots a fair game to play, but start really analyzing data - sweet real data, not BS data.


Pilots who participate in PPC and read this and agree, please let PPC know. (I won't.)

yuri_base

***On 2016-10-23, two guys went to Rochelle (only 2!) and set "world records" in distance and speed.

As a result, they essentially fucked up other capable guys who fly (relative to air) as good or almost as good as these guys, but are now far below in the table of records, for a long time (2 years already). Only because these 2 guys did "wind-shopping" and did a downwind jump in hurricane-strength uppers.

These "records" are as moronic as someone recording a GPS track of their run to bathroom on a jet liner, extracting a 100m length of it, and claiming on Wikipedia that they ran 100m in only 0.4s, much faster than Usain Bolt's 9.58s.

Here's my proposal to Paralog:

1. Stop this fucking nonsense, games with wind, fake "records", cheating.

2. Mandate the following rules, for any distance/speed track:

Rule A. The ground track must be a straight line with no more than 100m deviation from the line start-finish of 1000m altitude window.

Rule B. The ground track heading is established before each load as a line that is at an angle to cross-wind line (in downwind direction) equal to arctan of half wind speed divided by average horizontal speed of top 3 pilots in previous competition or maybe a test run before competing. This is to make the ground speed as close to air speed as possible, as the crosswind line will bisect the airspeed-groundspeed-windspeed triangle. Pilot's actual start-finish line should not deviate from this heading more than 5 degrees.

Rule C. No tracks are accepted if winds at 500m window level are more than 20kn. This is to minimize the difference between groundspeed and airspeed, since the bisecting cannot be done perfectly.

3. Standardize all speed results to sea level by dividing the speeds by a factor of [square root of (density at sea level) /divided by/ (density at middle level of 1000m window)]

4. Standardize all time results to sea level by multiplying the times by a factor of [square root of (density at sea level) /divided by/ (density at middle level of 1000m window)]

5. With wind-corrected ground tracks and standardized speeds and times, add calculated L/D to graphs according to the formula

L/D = (GR + z)/(1 - GR*z)

where z is dimensionless ratio z = ax/(g - ay), ax is horizontal acceleration, ay vertical, g acceleration due to gravity. (ax and ay are calculated from Vx, Vy data as derivatives.) GR here is glide ratio relative to air (which should be close to ground GR if the flights follow the above rules).

Then we can stop talking all this BS and cheating and not only give all pilots a fair game to play, but start really analyzing data - sweet real data, not BS data.


Pilots who participate in PPC and read this and agree, please let PPC know. (I won't.)

Who hurt you!?

Can you just post your derivations? No more nonsense.

Can you also explain why you think 3.567 is the magic L/D number and what that number translates to in wingsuit performance?

yuri_base

I proved Wingsuit Equations in 2006, see OP for the link.

Now, in modern civilized countries, there's this principle,

https://en.wikipedia.org/wiki/Presumption_of_innocence

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ei incumbit probatio qui dicit, non qui negat (“the burden of proof is on the one who declares, not on one who denies”)

So anyone who thinks that WSE and related math I derived is wrong, has a burden to rigorously, mathematically - not by just blah-blah-blah - prove that they are wrong.

Seriously? Seems like you're making the extraordinary claims here.

richoH

***I proved Wingsuit Equations in 2006, see OP for the link.

Now, in modern civilized countries, there's this principle,

https://en.wikipedia.org/wiki/Presumption_of_innocence

Quote

ei incumbit probatio qui dicit, non qui negat (“the burden of proof is on the one who declares, not on one who denies”)

So anyone who thinks that WSE and related math I derived is wrong, has a burden to rigorously, mathematically - not by just blah-blah-blah - prove that they are wrong.

Seriously? Seems like you're making the extraordinary claims here.

I don’t think he realizes he is the one who declares.

Ive flown a world record ws flight (in a smaller suit)

Time Flown: 6:30:18:00
Distance Flown: 924.42 km or 0 km (depending on interpretation of movement through air)
With Distance Fallen: 553.54 km and GR/LD of 1.67

And varified correctly (without need of a GPS)

There are 2 definitions of "proof". He's talking about mathematical proof, which only requires that the equations be mathematically correct.

However, even a mathematically correct equation can be complete rubbish if it treats physical principles incorrectly.

Which brings us to the second definition of "proof", which is actually demonstrating it in the real world and providing raw data...

aonsquared

There are 2 definitions of "proof". He's talking about mathematical proof, which only requires that the equations be mathematically correct.

However, even a mathematically correct equation can be complete rubbish if it treats physical principles incorrectly.

Which brings us to the second definition of "proof", which is actually demonstrating it in the real world and providing raw data...

Think he will provide either?

mccordia

Ive flown a world record ws flight (in a smaller suit)

Time Flown: 6:30:18:00
Distance Flown: 924.42 km or 0 km (depending on interpretation of movement through air)
With Distance Fallen: 553.54 km and GR/LD of 1.67

And varified correctly (without need of a GPS)

Here's how to set a world record of true wingsuit flight with infinite glide ratio, flying many miles without any loss of altitude (or even gaining altitude - negative GR).

Take a flatbed truck, install a large cage on it so it sits high enough to clear the cabin and be in clean airflow. Install a large 45-degree platform in it that deflects air. For a light pilot ("Pterodactyl") in a big suit, he should be able to surf the airflow at speeds of only perhaps 50-60mph.

This is:

- true contactless wingsuit flight
- it's not a windtunnel
- pilot is only supported by lift and drag

Can be used for training, aerodynamics research, etc.

Similar to this extreme sport gaining popularity:

[inline WingSurfing.jpg]

- but totally safe.

Are you incapable of answering simple questions?

What does your magical L/D number translate to for wingsuit performance?

Where is the mathematical derivation of your equations?

Where is the physical data to back up your mathematical derivation?

LeeroyJenkins

Are you incapable of answering simple questions?

What does your magical L/D number translate to for wingsuit performance?

Where is the mathematical derivation of your equations?

Where is the physical data to back up your mathematical derivation?

Still waiting Yuri.....

So, here's a suit back from 2009.

[inline 2009.jpg]

2018 suits... what's the difference from 2009, other than various gimmicks and slight changes in trim?

Other than my estimate of L/D = 2.8 from Matt G's flight off High Nose (short altitude flight, so most likely, average L/D was lower than the max, as short flights for max distance naturally lure the pilot into a slow flare after the start arc, to milk the initial energy into higher GR), there was no other reliable data, but I have a good reason think that the max L/D of that suit was about 3.0, virtually the same as of modern suits.

Just to illustrate my point that 2009-2018+ was and continues to be the era of The Great Stagnation in wingsuiting. All manufacturers copied this design and that was it, nothing new since then... The airplane-like design with separate wings was quickly abandoned, without even trying the basic thing all airplanes have - non-zero AoI.

yuri_base

So, here's a suit back from 2009.



2018 suits... what's the difference from 2009, other than various gimmicks and slight changes in trim?

Other than my estimate of L/D = 2.8 from Matt G's flight off High Nose (short altitude flight, so most likely, average L/D was lower than the max, as short flights for max distance naturally lure the pilot into a slow flare after the start arc, to milk the initial energy into higher GR), there was no other reliable data, but I have a good reason think that the max L/D of that suit was about 3.0, virtually the same as of modern suits.

Just to illustrate my point that 2009-2018+ was and continues to be the era of The Great Stagnation in wingsuiting. All manufacturers copied this design and that was it, nothing new since then... The airplane-like design with separate wings was quickly abandoned, without even trying the basic thing all airplanes have - non-zero AoI.

LOL at thinking all wingsuits are copied off of Shorb's old suit - or even that it was all that different from the suits that came before it. (Yes, I recognize it and even have pictures of it from back in the day.) Suit design has changed a lot. As has performance. No, we don't need a pitot tube to prove it.

There's definitely a CoW in this thread, and he's the one avoiding questions. I'm back to my comment about unsubstantiated mathsturbation. Seems like the models aren't substantiated - at least based on the reviews so far. I guess the world still isn't ready for the Yuri Device (remember when it was called that?)

yuri_base

First constructive comment in this thread, much appreciated!

***what are your concrete suggestions to WS manufacturers? If you had a factory for a day what would you build?

1. Explore putting the body at zero AoA (like airplane's fuselage) and varying AoI (angle of incidence) of both arm and leg wings (requires separate arm/leg wings, like in old style suits, and leading edge on the leg wing, like Vampire series). Make several suits with 5 degree increment in AoI, study their max L/D using, for example, L/D Vario on a vane. The pilot, of course, needs to learn new style of flying, where the body is in line with the airflow, creating minimal drag and zero lift (all lift is generated by wings only). The idea is (like in airplanes) to exclude the very inefficient generator of lift - body/fuselage - as much as possibly, leaving pretty much only its cross-sectional drag.



2. Explore a sealed, weakly inflated (just a bit above dynamic pressure in flight) shaped leading edge made of rubber (like a bike inner tube, but profiled), with significantly more forward extension (3 inches?) than current foam inserts, yet having minimal force added for pull, etc. In attempt to make a really nice airfoil profile, not what we have now with big radius of curvature on the leading edge, which creates a lot of drag. Quantify the improvements with L/D Vario.

3. Combine 1&2. Quantify the improvements with L/D Vario.

4. Make a wingsuit with foam wings (closed cell polyurethane foam like one used in cushions, etc.) This will eliminate the need for inflation and big scoops creating drag. I've started making a prototype long time ago (2010-ish) but haven't finished and haven't flown it (the leg wing was almost done, but I don't have it with me now to post a picture). The foam is easily foldable, so the pull should not be more difficult than with regular suits. The foam wing will maintain the airfoil shape more precisely than inflated fabric can. (Also, possibly to try stepped airfoil.) The leg wing should have a large leading edge (i.e. it should start in the knee area) to maximize its efficiency, not just be a surface where de-energized, turbulent air rolls over it. The wings should have a non-zero AoI as in #1. Better yet, make wing attachment with adjustable AoI (on the ground, not dynamically in the air). Quantify the improvements with L/D Vario.

5. Superman's half-wingsuits (leg wing only). Flying with arm(s) stretched forward, or in regular tracking position. Need to fine tune the trim/balance, since with my half-V-4 stretching arms forward was producing too much "front momentum" (not enough momentum from the leg wing). Quantify the improvements with L/D Vario, compared to tracksuits. Quantify max horizontal speed and set a new world record, leaving full wingsuits in the dust! (since it's naturally close to L/D=1.4 and lacks extra fabric of full wingsuit which at this L/D is only a burden)

6. In A/B tests, quantify the effects of [in my opinion, gimmicks] innie-outie, cross-hatched fabric (?) on the bottom surface of arm wings, rubber-like leading edge material. Remove them if they, indeed, turn to be just gimmicks ("this material is used in space shuttle!" type of BS)

7. Quantify effects of various elements on max L/D, just to know, how much of a bite each is taking off the absolute max performance: helmets, cameras, shoes with flaring out soles (like on most sneakers), various rigs.

8. Study the effect of increasing surface area on L/D to see if the curve (L/D) vs. S shows an asymptotic slowdown or there's still some potential.

9. Make a gigantic suit similar to Antoine Laporte's and measure its max L/D precisely.

10. Make goal-specific wingsuits for speed, time, and distance rounds in competitions. The slowest (in fall rate) wingsuits will be amazing for BASE starts! (will be almost a ground launch). A giant suit with ridiculously thick airfoil. For speed, probably Superman's half-suit. For distance, probably #1 or #4. Let the pilots use 3 different suits in competitions! In triathlon, they don't require athletes to run and swim while carrying their bicycle, do they? Each round requires a specific tool, why not in wingsuit competitions?

11. Make a compact, low drag air intake on the helmet or short tubes protruding from armwings, with the delivery of ram air into wings via flexible tubing, to eliminate large draggy scoops altogether.

12. Overall, explore the old split-wings designs more, since no scientific study like this has been done in their era in early 2000's. I believe they still have the potential if we're made to look like little airplanes, rather than mattressy squirrels.

Should be plenty for a day...

platypii

Proper aerodynamic instrumentation would be great, because GPS is useless when comparing between different skydives. But does it offer anything over flying next to someone? My understanding is that WS manufacturers do iterative development by flying next to people they fly with all the time, and see what effects are of suit changes. By flying relative to another person, the wind effects are irrelevant, and you can see if you can edge ahead of them, or out float them.

No, I don't think so. People are different, differences between them and the variations in flying of the "reference" pilot are not as precisely quantifiable as aerodynamic instrumentation. In aviation, they study planes with instrumentation, not flying relative to another plane. Dynamic effects (slow planeout/flare) also cannot be excluded (while L/D Vario excludes it in real time, since L/D measured by accelerometer is not affected by "fake" changes in glide ratio).

platypii

Based on your models, do you think we should be working more on increasing lift (surface area)? Or more work on decreasing drag? How do the wingsuit equations help inform which changes to try?

WSE cannot say which one to work more on, lift or drag. As "magic" L/D's show (1.414, 2.61, 3.567), the dynamic behavior of gliders does not depend on the nature or their absolute lift or drag, only on their ratio, L/D. For example, sqrt(2) as the L/D for max horizontal speed, applies to both wingsuits and canopies or other gliders (hang-, para-). As mentioned before, L/D is like a reverse of coefficient of friction, one should make coefficient of friction lower. So, we should always strive to increase L/D by all means, even if it means decreasing lift, but decreasing drag even more so that L/D grows.

I think that airplane-like planform, with proper AoI and wide leading edge on the leg wing (much wider than on Vampires) still has a healthy unexplored potential. The mattresses reached L/D=3.0, in my opinion, purely by dumbly increasing surface area which makes the negative contribution from the body in overall performance less noticeable (like diluting very salty water with clean water makes it less salty).

*crickets*

Nice Dodge, answer these.

What does your magical L/D number translate to for wingsuit performance?

Where is the mathematical derivation of your equations?

Where is the physical data to back up your mathematical derivation?


Can someone repost these questions? I don't know if he is just ignoring me or he blocked me so he doesn't even see my comments.

LeeroyJenkins

Nice Dodge, answer these.

What does your magical L/D number translate to for wingsuit performance?

Where is the mathematical derivation of your equations?

Where is the physical data to back up your mathematical derivation?


Can someone repost these questions? I don't know if he is just ignoring me or he blocked me so he doesn't even see my comments.

We can see them. No idea if he can.

LeeroyJenkins

Where is the mathematical derivation of your equations?

http://www.pureflyingmagic.com/Content/Knowledge/Resources/Articles/en/WingsuitEquations.pdf

LeeroyJenkins

Where is the physical data to back up your mathematical derivation?

You don't need physical data to prove it. If you accept the underlying physical equations: F=ma and lift equation, and if there are no mistakes in the proof (I don't see any, but onus is on you to find one), then the equations are valid.

That being said, I've played with them, and applied them to real world gps data, independently of yuri's software, and they appear to match observed reality. For example with wingsuit starts... using WS equations you can observe the L/D being close to 3:1 throughout the whole start arc, whereas the GPS glide ratio varies wildly and takes much longer to reach "steady state". This is what I would expect to see from a true L/D measurement.

platypii

***
Where is the mathematical derivation of your equations?

http://www.pureflyingmagic.com/Content/Knowledge/Resources/Articles/en/WingsuitEquations.pdf

LeeroyJenkins

Where is the physical data to back up your mathematical derivation?

You don't need physical data to prove it. If you accept the underlying physical equations: F=ma and lift equation, and if there are no mistakes in the proof (I don't see any, but onus is on you to find one), then the equations are valid.

That being said, I've played with them, and applied them to real world gps data, independently of yuri's software, and they appear to match observed reality. For example with wingsuit starts... using WS equations you can observe the L/D being close to 3:1 throughout the whole start arc, whereas the GPS glide ratio varies wildly and takes much longer to reach "steady state". This is what I would expect to see from a true L/D measurement.

The number of people in the Solar System (and possibly, in the Universe) who understand Wingsuit Equations and their value, has just quantum-leaped to THREE.

We might reach 4 by the year 2019, 2020, 2022, 2025 2030, or... never - but this might need a poll.

Maybe, time to start the WSE number system:

WSE #1 - Yuri
WSE #2 - Hartman
WSE #3 - Kenny

platypii

***
Where is the mathematical derivation of your equations?

http://www.pureflyingmagic.com/Content/Knowledge/Resources/Articles/en/WingsuitEquations.pdf

LeeroyJenkins

Where is the physical data to back up your mathematical derivation?

You don't need physical data to prove it. If you accept the underlying physical equations: F=ma and lift equation, and if there are no mistakes in the proof (I don't see any, but onus is on you to find one), then the equations are valid.

That being said, I've played with them, and applied them to real world gps data, independently of yuri's software, and they appear to match observed reality. For example with wingsuit starts... using WS equations you can observe the L/D being close to 3:1 throughout the whole start arc, whereas the GPS glide ratio varies wildly and takes much longer to reach "steady state". This is what I would expect to see from a true L/D measurement.

Of course you need physical data to back up theoretical calculations. Just because mathematical derivations are correct does not mean the equations are a valid representation of wingsuit flight. Accept F=MA, you and yuri sound like freshman in physics that think they have the world figured out. Where is the scientific method?

I’ve played with the WS equations and used my GPS data in them and gotten absolute nonsense as an output. I believe there could be value to wingsuit specific equations if they were developed by someone that understands dynamics and are properly validated with 3D modeling and wind tunnel testing.


As for now Yuris crack pot equations are unproven pshdoacience.

LeeroyJenkins

Of course you need physical data to back up theoretical calculations. Just because mathematical derivations are correct does not mean the equations are a valid representation of wingsuit flight. Accept F=MA, you and yuri sound like freshman in physics that think they have the world figured out. Where is the scientific method?

Maybe you missed the part where I followed up with real world experience? And also explained how one can test if experience lines up with theory?

Jump from a cliff, where you nail the angle of attack, hold the same body configuration through the whole flight, and then flare for deployment. Hypothesis: once up to speed, your L/D should be roughly constant throughout the flight. Here is an example of such a flight.

[inline ld.png]

You can see the l/d (purple line) quickly goes up to approximately 3.0 glide ratio, improves slightly with a bit more speed (typical of glider polar curves), and stays roughly constant through the flare at the end before deployment.

Contrast with the glide ratio (green line) which starts low and takes nearly 10s to reach 3:1. Then some speed is converted into glide and so it continues rising to above 5:1 glide. But the debt must be paid, and so the glide ratio drops off below 3:1 before the flare. The flare again brings the instantaneous glide above 5:1 before the canopy opens.

Data supports the theory. 1 track, small sample size? Sure. But I've seen this pattern over and over again on baseline. And since it agrees with the theory, and the intuition, and the data, I'm not sure why you are so skeptical? It provides an additional, more aerodynamically interesting, measure of wingsuit flight.

platypii

Hypothesis: once up to speed, your L/D should be roughly constant throughout the flight. Here is an example of such a flight.

You don't need yuri's equations for that. Any glider pilot knows that on a constant airspeed and constant glide, your L/D ratio is roughly constant. What's new?

Also, how was the green line calculated?